The present invention relates to a method and device for electric arc welding, underwater or within a liquid.
The method is particularly suitable although not exclusively, in the field of submerged welding in deep water with a coated electrode to be used on carbon or stainless steels.
In general, underwater electric welding or welding in "deep water", is a difficult operation, which necessitates considerable precautions due to the risks undertaken by the diving welder associated on the one hand with diving, and on the other hand with presence of electricity. Poor visibility, floating condition for the diving welder which lead to irregular and inaccurate movements, molten metal rapid cooling, slag rapid cooling if so, render fusion bath control by the welder more difficult.
Different methods and devices for underwater electrical welding are already known. Their field of application is however limited and these methods are no longer satisfactory under certain conditions like for example: with austenitic electrodes, in case of thin walls welding or welding at great depth, etc. Good quality weldings are thus not obtained. In fact, due to high ionization potential of water and the pressure exerted by water on the welding arc, the striking and sustaining of said welding arc are difficult to obtain. In case of extinction, due to electrode cooling, water does not permit easy restriking of the arc either. And when there are frequent stops and welding resumptions by the welder, welds obtained show unacceptable cracks, porosities, blisters and/or occlusions of impurities.